Get Fit__ Running In The Summer Doesn’t Just Feel Harder, It Is Harder
Turns out all those times that you swore running in the summer was harder, you were actually right. Running outside in the heat has been proven to require more energy and be harder than running in cooler temps.
When you’re on a run, only about 30% of your energy is going towards moving your body. The rest is actually going towards cooling you down, so the hotter it is, the more energy you need to do that.
Exercise physiologist and nutrition scientist Stacy Sims, PhD, says, “"You’ll find your heart rate is higher and the intensity feels harder.” When you run in the heat, more blood flows to your skin than to your muscles, which is what makes it more difficult.
As if the hotter temperatures making it harder to run weren’t enough, there are a few more factors that make summer jogs more difficult. Humidity is one of them. When there’s lots of moisture in the air, it’s harder for your sweat to evaporate off your body, so you can’t cool off quite as quickly. UV rays are also a factor since sunburn diverts blood flow away from your muscles and towards your skin, just like heat. According to Dr. Sims, “Recent research has shown that the skin temperature has a bigger effect on performance than actual core temperature. If you can keep your skin cool, you will keep more blood in central circulation, allowing for better exercise performance even if your core temperature is elevated more than exercise-normal.”
This doesn’t mean you should take the summer off, though. It just means you have to work a little harder, but it’ll all be worth it in the end.